JP2019529811A - Wave energy capture system - Google Patents

Abstract

A method, system and apparatus 10 for capturing wave energy is disclosed. The underwater wave energy capturing device 10 includes a pipe 12 and a plurality of one-way valves 21, 31, 41. The pipe 12 has a seawater inlet 11 at the upstream end 10 u of the pipe 12. The downstream end 10 d of the pipe 12 can communicate with the energy utilization means 2 that is powered by the seawater flow from the pipe 12. One-way valves 21, 31, 41 divide tube 12 into a series of chambers 20, 30, 40. The chamber includes elastic walls 22, 32 and 42. These can be modified to change the effective internal volume of each chamber 20, 30, 40. The valves 21, 31, 41 open to allow downstream water flow in the tube 12, and close the valve 21, 31, 41 to resist upstream water flow in the tube 12.

Description

  The present invention relates to a method, apparatus and system for capturing wave energy, particularly from subsurface waves.

  Wave energy devices are provided in various forms. One type of wave energy device utilizes tidal ascent and descent motion, for example, utilizing a buoyancy member that acts on a stationary member secured to the seabed. The rising and falling movements of the tide are relatively predictable and regular, making them relatively uncomplicated sources from which wave energy can be extracted.

  Near the shoreline where wave energy devices can be more easily installed and maintained, subsurface wave tides and flows that move alternately along the sea floor provide a more powerful source of wave energy to be captured. However, such wave energy is irregular and unpredictable. Therefore, it is difficult to utilize a regular and continuous energy source, and it is also difficult to optimize the power generation equipment for operating efficiency within a specific power band.

  In addition, wave energy devices installed near the coastline must be more sensitive to environmental factors including marine life and human activities such as sea bathing and boating. Turbines cause problems such as blade collisions and noise, the latter being particularly detrimental to marine life that relies on echo location.

  The present invention has been made in view of such a background.

  According to a first aspect of the invention, there is provided a wave energy capture device comprising at least one of a tube and a plurality of one-way valves. Preferably, the wave energy device can be completely submerged. Thus, the wave energy device may be configured to capture energy from subsurface waves.

  Preferably, the apparatus includes a tube having a seawater inlet at the upstream end of the tube. Ideally, the downstream end of the tube can communicate with the energy utilization means. The energy utilization means may be powered by a seawater flow from the tube. The one-way valve can be arranged to divide the tube into a series of chambers. Each chamber has an elastic wall. Ideally they can be modified to change the effective internal volume of each chamber.

  Preferably, each of the valves is configured to be open to allow downstream water flow in the tube. Preferably, each of the valves is configured to be closed to resist upstream water flow in the tube.

  Preferably, at least one of each chamber is configured to expand in response to a downstream flow of water into the at least one chamber within the tube.

  Preferably, the valve proximal to the inlet is configured to open in response to a flow of water entering from the inlet. Preferably, the valve proximal to the inlet is configured to close in response to the flow of water flowing out of the inlet. The inlet can consist of a funnel.

  Preferably, the apparatus further comprises a water permeable shell surrounding at least one of the chambers. The shell can be configured to limit expansion of the chamber or the elastic wall of each chamber. The shell can consist of a mesh.

  Advantageously, the use of a shell allows the material from which the elastic wall is constructed to be more sensitive to changes in water pressure, thereby increasing the energy capture capability of the device. In particular, the elastic wall may be thinner or more elastic than otherwise practical in a marine environment where tidal forces are highly variable. The use of a shell increases the sensitivity of the device to small forces without significantly increasing the burden of the device on damage from large forces.

  Preferably, the internal volume of the region of the shell surrounding each chamber substantially defines the maximum volume of the respective enclosed chamber.

  Preferably, the chamber located closer to the upstream end has a larger average perimeter compared to the chamber located closer to the downstream end.

  Preferably, the tube tapers inward from the upstream end toward the downstream end.

  Preferably, the one-way valve located closer to the upstream end has a larger opening through which fluid flows compared to the one-way valve located closer to the downstream end.

  Preferably, the one-way valve or each one-way valve includes a plurality of flexible valve members, and each flexible valve member is connected to the inner peripheral surface of the pipe via a root portion around the flexible valve member. Preferably, the one-way valve or each one-way valve is a bicuspid valve or a tricuspid valve. The apparatus can comprise an inlet filter. Many devices include an inlet cover.

  According to a second aspect of the invention, there is provided a system for utilizing energy from a device according to the first aspect of the invention. The system may be a power generation system. The system can comprise a turbine and a generator. The system can comprise a plurality of devices according to the first aspect of the invention, ideally having respective downstream ends connected to a common energy utilization means. The system can include one or more anchors for securing the device to the seabed. The system can include one or more tethers for connecting between the device and the anchor. The system can comprise an adjustable tether system for controlling the device or the depth of each device.

  According to a third aspect of the present invention, a method for capturing wave energy is provided. The method can include using an apparatus according to the first aspect of the invention and / or a system utilizing energy according to the second aspect of the invention. The method can include at least one of the following steps.

Providing a tube with an inlet at the upstream end, the tube being divided into a series of chambers by a plurality of one-way valves configured to be open to allow downstream flow of water within the tube; Each one-way valve is configured to be closed to resist upstream water flow in the pipe,
Soak the tube in sea water,
The downstream end of the tube is connected to energy utilization means.

  It should be understood that the features and advantages of the different aspects of the present invention may be combined with or replaced with one another as the context allows.

  For example, the apparatus and / or system features described in connection with the first and / or second aspects of the invention are provided as part of the method described in connection with the third aspect of the invention. can do. For example, the method can include providing a water permeable shell and positioning the water permeable shell to surround at least one chamber.

  Furthermore, such features themselves may constitute further aspects of the invention. For example, the features of the adjustable tether system may itself constitute a further aspect of the present invention.

In order that the present invention may be more readily understood, embodiments thereof will now be described by way of example with reference to the accompanying drawings.
FIG. 1 is a schematic cross-sectional view of a subsurface wave power generation system incorporating a wave energy capture device according to a first embodiment of the present invention. FIG. 2 is a schematic diagram showing the wave energy capturing device of FIG. 1 separately. 3 is a schematic cross-sectional view, partially enlarged, of a representative series of chambers of the wave energy capture device of FIG. FIG. 4 is a schematic view of a subsurface wave power generation system incorporating a wave energy capturing device according to a second embodiment of the present invention.

  FIG. 1 is a schematic cross-sectional view of an energy generation system 1 that operates by ocean waves below the surface of the water. The system 1 includes an energy utilization system 2 and a wave energy capturing device 10 according to the first embodiment of the present invention.

  The energy utilization system 2 includes a generator 3, an electric cable 3 a, an electric load 3 b, a turbine 4, and a pipe 6. The generator 3 is electrically connected to an electric load 3b via an electric cable 3a. The generator is mechanically powered by the turbine 4, and the turbine 4 is mechanically powered by a water stream input to the turbine 4 from the pipe 6. The turbine 4 includes a discharge port 5 as a water outlet. The pipe 6 guides water from the downstream end 10 d of the wave energy capturing device 10 to the turbine 4.

  The wave energy capturing device 10 includes an elongated tapered water pipe 12 having a substantially annular cross section extending between a downstream end 10d and an upstream end 10u of the device 10. Accordingly, the tube 12 generally shares the same downstream end 10 d and upstream end 10 u as the wave energy capture device 10. The funnel-shaped inlet 11 is provided at the upstream end 10u.

  Furthermore, the tube 12 and the wave energy capture device 10 are generally coiled similar to a nautilus shell. This is indicated by the dotted line 10s in FIG. 1, but it should be noted that the dotted line 10s does not necessarily form part of the physical structure of the wave energy capture device 10, but rather shows its schematic shape. I want to be. The tube 12 tapers inward toward the downstream end 10d, and includes an elastic wall that is substantially impermeable to water and can be deformed to change the effective volume of the tube 12.

  The wave energy capture device 10 further includes a series of one-way valves that divide the tube 12 into a series of chambers. Only the first, second and third chambers 20, 30, 40 are representatively shown in FIG. 1, and are close to the upstream end 10u in this order. However, there is an additional chamber between the upstream end 10u and the downstream end 10d of the tube 12. Each of the illustrated chambers 20, 30, 40 is delimited by corresponding first, second and third valves 21, 31, 41, which are present in the wave energy capture device 10. While representative of other valves, the other valves have been omitted from FIG. 1 for clarity.

  In general, two successive valves and a portion of the wall of the elastic tube 12 between them define a respective chamber. Thus, each chamber has an elastic wall that can be deformed to change the effective internal volume of the chamber. However, it should be noted that the circumferential region of the tube 12 adjacent to each valve may be reinforced to prevent deformation or deflection so as to maintain the reliability of operation of each valve.

  Due to the taper of the tube, the valve located closer to the upstream end 10u has a larger opening through which the fluid flows compared to the valve located closer to the downstream end 10d. Furthermore, the chamber located near the upstream end 10u has a larger average perimeter than the chamber located near the downstream end 10d. As shown in FIG. 1, the largest chamber 20 is the chamber that is continuously closest to the upstream end 10 u, and the chamber 20 is conceptually per unit length more than the chambers 30 and 40 that continue in succession. The seawater volume that can be accommodated is large. This is based on the fact that the chambers 20, 30, 40 are subjected to the same internal pressure and external pressure. When the internal pressures of the chambers 20, 30, 40 are the same and the pressure outside the wave energy capturing device 10 is also the same, the corresponding elastic wall portions 22, 32, 42 of each chamber are shown in FIG. It should also be noted that it does not deform from a position that is not subjected to the original stress.

  Referring briefly to FIG. 2, where the schematic diagram of the wave energy capture device of FIG. 1 is shown alone, the wave energy capture device 10 further comprises a network permeable shell 13, which is a tube 12. It is arranged outside. This also roughly follows the same shell-like profile, but with a periodic wavy bulge consistent with the respective chamber 20, 30, 40 of the wave energy capture device. Further, the maximum circumference of each bulge substantially coincides with the center in the axial direction of each chamber. The minimum circumference of the shell 13 between each bulge approximately coincides with the axial boundary between two adjacent chambers and therefore coincides with the position of the valve. Thus, the shell 13 has a series of regions, each region of the shell surrounding a respective chamber.

  Specifically, referring back to FIG. 1, the first chamber 20 defined by the first and second valves 21, 31 and the first elastic wall portion 22 is defined by the second shell region 23. Besieged. The second chamber 30 defined by the third and third valves 31, 41 and the second elastic wall portion 32 is surrounded by a second shell region 33. The third chamber 40 is defined by a third valve 41, a fourth valve (not shown) and a third elastic wall portion 42 and is surrounded by a third shell region 43.

  Each one-way valve in the present embodiment is in the form of a tricuspid valve that is well known in the art of artificial heart valves. An example of such a tricuspid valve is disclosed in US Pat. No. 4,222,126, the contents of which are hereby incorporated by reference to the extent permitted by applicable law.

  Each valve has three flexible valve members, and each valve member is connected to the inner peripheral surface of the tube 12 through a root portion around the valve member. Only two of the three valve members are shown in FIG. 1, since the valve is only schematically shown in FIG. However, referring to FIG. 2, all three valve members 21a, 21b, 21c of the first valve 21 are shown. Subsequent valves are also represented as having three valve members. However, in both FIGS. 1 and 2, the elastic wall portion of each chamber is unstressed, the valve is in the closed position, and the valve members are biased toward each other to seal each chamber. The contacting isobaric state is shown.

  Further, each valve is arranged to close in response to a water flow in the upstream pipe toward the upstream end 10u. Thus, each valve resists this upstream water flow. Conversely, each valve is arranged to open in response to a water flow in the downstream pipe toward the downstream end 10d. In other words, the pressure differential between each valve substantially opens the valve only if the upstream water pressure is greater than the water pressure downstream of the valve.

  Therefore, the flow of water toward the funnel-shaped inlet 11 caused by waves below the water surface causes the valves 21, 31, 41 to open in order. This is illustrated in FIG. 3, which shows an enlarged cross-sectional schematic view of a portion of the wave energy capture device 10 having first, second, and third chambers 20, 30, 40. Also, only two of the three valve members of each of the first, second and third valves 20, 30, 40 are shown.

  As shown by the arrow F, the water flow is concentrated by the funnel-shaped inlet 11, and the water pressure upstream of the first valve 21 is higher than the water pressure downstream of the valve 21 in the chamber 20. Accordingly, the valve members 21 a and 21 b are separated so that water can flow into the first chamber 20. At the same time, the increase in pressure inside the chamber 20 relative to the water pressure outside the chamber 20 causes the elastic wall portion 22 of the first chamber 20 to expand. Similarly, the water flow continues to the second chamber 30 and the third chamber 40, etc., and the valve members 31a, 31b, 41a, 41b are spaced apart to flow water into the chambers 30, 40, and the respective elastic walls. Portions 32 and 42 expand in response to increasing pressure within each chamber 30 and 40.

  Expansion of each wall portion of the tube 12 is limited by the respective region of the shell 13. Specifically, expansion of the first wall portion 22 is restricted by the first shell region 23, expansion of the second wall portion 32 is restricted by the second shell region 33, and the third wall portion 42 is Expansion is limited by the first shell region 43. Thus, the internal volume of the shell region surrounding each chamber substantially defines the maximum volume of each chamber.

  Thus, the water moves under the action of waves below the surface of the water along the continuous chamber of the tube 12, thereby driving the energy utilization means 2.

  Under conditions where waves below the water surface travel in the opposite direction from the inlet 11 and the pressure in the first chamber 20 is larger than the pressure just outside the inlet 11, the valve members 21a and 21b are in close contact with each other, Outflow from the first chamber 20 to the outside is prevented. Similarly, if the pressure in any upstream chamber is lower than the pressure in the adjacent downstream chamber, the valve between these adjacent chambers closes to prevent upstream water flow toward the upstream end 10u.

  Furthermore, due to the irregularity and local nature of ocean waves, there are many pressure fluctuations at different locations outside the wave energy capture device 10. This works with the deformable elastic wall portion of the tube 12 and creates a pressure differential between the chambers. If there is more pressure in the upstream chamber compared to the adjacent downstream chamber, the valve between them opens. If there is more pressure in the downstream chamber compared to the adjacent upstream chamber, the valve between them closes. Further, when the external pressure of the wave energy capture device 10 is higher than the internal pressure, the deformable wall portion of the tube 12 is squeezed to expel water from the downstream end 10 d of the wave energy capture device 10. Furthermore, the taper structure of the pipe 12 in which the upstream end 10u is wider than the downstream end 10d promotes water flow in the downstream direction.

  As described above, the first embodiment described with reference to FIGS. 1-3 does not unduly disturb the water flow through the tube 12 of the wave energy capture device 10, but fixes the wave energy capture device 10 to the seabed. In order to greatly facilitate the transportation and installation of the wave energy capturing device 10, it is wound in a coil shape. However, the wave energy capturing device 10 does not necessarily have to be wound in a coil shape.

  FIG. 4 shows an alternative second embodiment of the present invention in which the wave energy capture device 10 extends linearly. The second embodiment has the same principle features and features as the first embodiment, and the same reference numerals are used to indicate the same features. The wave energy capture device 10 of this second embodiment is shown schematically in FIG. 4 as having ten chambers 20, 30, 40, 50, 60, 70, 80, 90, 100.

  Specifically, FIG. 4 is a schematic diagram of the power generation system 1 using wave power below the water surface that includes the wave energy capturing device 10 according to the second embodiment. The system 1 includes the energy utilization means 2 as already described with respect to the first embodiment.

  The system 1 is further shown in FIG. 4 to include an inlet filter 14 and an inlet cover 15. Although the inlet filter 14 is shown separately from the inlet 11, in practice, in order to prevent objects such as sea debris and marine life from entering the tube 12, Placed in. The inlet cover 15 can also be positioned over the inlet 11 to control the wave force received by the device, and the partial covering directs only a portion of the total wave force into the device 10. . The inlet filter 14 and the inlet cover are also provided as part of the first embodiment of the present invention, even if not explicitly shown in FIGS.

  During actual use of the device according to any embodiment of the present invention, it may be necessary to control the depth of the device 10. During periods of high tidal activity, it may be desirable to place the device closer and deeper to the sea floor so as to prevent damage while maintaining device operation. Conversely, during periods of low tidal activity, the device can be brought closer to the surface of the water, so that more noticeable entrainment and flow forces below the surface near the surface of the water can cause the device 10 to operate efficiently. Enough.

  For this purpose, the device 10 may be connected to one or more anchor points on the seabed via an adjustable tether system. As the wave energy increases beyond a predetermined amount, the adjustable tether system can be configured to automatically pull the device toward the seabed to prevent damage. Conversely, as the wave energy decreases, the adjustable tether system can be configured to automatically release the device so that the device can rise toward the surface. Such an adjustable tether system may be mechanically powered by wave energy, and therefore the depth of the device according to this embodiment may be proportional to the wave force. Alternatively, the adjustable tether system may be at least partially electrically driven.

  Furthermore, the wave energy capture device 10 according to the embodiment of the present invention has a predetermined buoyancy that optimizes the depth and the force necessary to control the rate of change in depth in response to a sudden change in wave energy. Can have. This can be achieved by providing a buoyancy device that acts at least in part on the wave energy device. These may be, for example, in the form of a water surface buoy and / or a subsurface buoy attached to the wave energy capture device 10 via a buoy line. Advantageously, providing a water surface buoy can be useful both for controlling the depth of the wave energy device and for easily indicating the position of the wave energy device. Thus, the wave energy device is less likely to be unintentionally damaged by transportation traffic and can be more easily deployed for maintenance.

  Alternatively, different sets of devices 10 according to embodiments of the present invention may be placed at a predetermined fixed depth. In such a case, one or more covers 15 may be provided. During periods of high tidal activity, the cover 15 is assumed to protect devices placed at a shallower depth. Conversely, when the tidal activity is low, the cover can be bypassed to a deeper device. This is to prevent the operation of such deeper devices not to protect them but to sub-optimal efficiency.

  Such a cover may be driven by an adjustment system similar to that described above in connection with the adjustable tether system and is mechanically powered from wave energy alone or incorporates an electrically powered aspect. One of them.

  If the device 10 according to an embodiment of the invention is arranged at a certain depth, this can be achieved by attaching it to a platform fixed to the seabed. Such a platform may be embedded therein or otherwise configured to protect the energy utilization means 2 powered by devices according to various embodiments of the present application. . In such “constant depth” embodiments, the buoy may be provided as a means for indicating the position of the wave energy device.

  The inventor of the present invention has been inspired by the human cardiovascular system, particularly the cardiovascular system's ability to maintain a relatively constant blood flow even during arrhythmias. It has gained. Device 10, along with its elastic wall 12 and tricuspid valve, mimics cardiovascular aspects and advantages. Embodiments of the present invention provide a wave energy capture device 10 that can convert irregular and unpredictable subsurface wave forces prevailing near the coastline into a more predictable and regular water flow. I will provide a. That is, the wave energy capture device 10 can convert irregular and unpredictable subsurface wave forces that are widely distributed near the coastline into a more predictable and regular water flow. This can lead to powering the turbine 4 optimized to efficiently convert such a regular flow of water into electricity.

  While the present invention is believed to be particularly effective in connection with a turbine, other energy utilization means 2 are also contemplated. For example, water may be pumped up to an inland reservoir, according to embodiments used in conjunction with conventional hydropower systems.

  Furthermore, you may provide the several wave energy apparatus 10 which concerns on embodiment of this invention as a part of the system for electric power generation. The water flow output from the downstream ends 10d of the plurality of devices can be combined into a single pipe 6 to supply the turbine 4 with more regular water flow power than the single device 10 according to the present invention. The increase in regularity is due to the averaging effect of the individual flow combinations.

  In alternative embodiments of the invention, other features may be provided in addition to or instead of the features described herein. For example, multi-cusp valves are used in the described embodiments and are generally preferred because of the similarities and advantages associated with the cardiovascular system, but alternative one-way valves are possible replacements. These can have flexible valve members. Alternatively, they can have an induced rigid valve member that is shaped, for example, as a ball, ring or hinge, and is optionally spring loaded towards the closed state.

  Many different types of energy utilization are possible. This embodiment is directed to utilizing energy from the water stream output from the device to generate electricity. However, this kinetic force can be used in other ways, such as driving the machine directly, or other methods known in the art.

  Although the present invention has been described in connection with specific embodiments thereof, many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the scope of the appended claims.

Claims (22)

Tube,
A seawater inlet at the upstream end of the pipe, and a downstream end of the pipe capable of communicating with energy utilization means powered by the seawater flow from the pipe;
A plurality of one-way valves that divide the tube into a series of chambers;
Each chamber has a deformable elastic wall that changes the effective internal volume;
Each one-way valve is configured to open to allow downstream water flow in the tube and is configured to close to resist upstream water flow in the tube. Underwater wave energy capture device.   The underwater wave of claim 1, wherein at least one of each chamber is configured to expand in response to a downstream flow of water within the tube into the at least one chamber. Energy capture device.   The one-way valve proximal to the inlet is configured to open in response to a flow of water entering from the inlet and configured to close in response to a flow of water flowing out of the inlet. The underwater wave energy capturing device according to claim 1 or 2.   4. The permeable shell according to claim 1, further comprising a water permeable shell surrounding at least one of the chambers and configured to limit expansion of the chamber or the elastic wall of the chamber. Underwater wave energy capture device.   The underwater wave energy capture device of claim 4, wherein the internal volume of the region of the shell surrounding each chamber substantially defines the maximum volume of the respective chamber enclosed.   The underwater wave energy capturing device according to claim 4 or 5, wherein the shell is made of a mesh.   The underwater wave energy capturing device according to any one of claims 1 to 6, wherein the inflow port includes a funnel.   The underwater wave energy capture according to any one of claims 1 to 7, wherein the chamber located closer to the upstream end has a larger average perimeter compared to a chamber located closer to the downstream end. apparatus.   The underwater wave energy capturing apparatus according to claim 1, wherein the pipe tapers inward from the upstream end toward the downstream end.   The one-way valve located closer to the upstream end has a larger opening through which fluid flows compared to the one-way valve located closer to the downstream end. The underwater wave energy capturing device according to claim 1.   The one-way valve or each one-way valve includes a plurality of flexible valve members, and each of the flexible valve members is connected to an inner peripheral surface of the tube via a root portion around them. The underwater wave energy capturing device according to claim 1, wherein   The underwater wave energy capture device according to any one of claims 1 to 11, wherein the one-way valve or each one-way valve includes a multi-cusp valve.   The underwater wave energy capturing device according to claim 1, further comprising an inflow filter.   The underwater wave energy capturing device according to claim 1, further comprising an inflow port cover. In the electric power generation system for utilizing the energy from the underwater wave energy capture device according to any one of claims 1 to 14,
A power generation system comprising a turbine powered by a water flow from the underwater wave energy capturing device and a generator.   The power generation system of claim 15, further comprising one or more anchors for securing the underwater wave energy capture device to the seabed.   The power generation system of claim 16, further comprising one or more tethers for connecting between the underwater wave energy capture device and the one or more anchors.   The power generation system of claim 17, further comprising an adjustable tether system for controlling a depth of the underwater wave energy capture device relative to the seabed.   The power generation system according to any one of claims 15 to 18, comprising a plurality of the underwater wave energy capturing devices according to any one of claims 1 to 14.   A method for capturing wave energy using the underwater wave energy capturing device according to any one of claims 1 to 14 and / or the power generation system according to any one of claims 15 to 19. A tube having an inlet at the upstream end is provided and the tube is divided into a series of chambers by a plurality of one-way valves configured to be open to allow downstream water flow within the tube. Each one-way valve is configured to be closed to resist upstream water flow in the tube;
Soak the tube in sea water,
21. The method of claim 20, wherein the downstream end of the tube is connected to an energy utilization means.   An apparatus, system or method substantially as herein described with reference to the accompanying drawings.

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